Evidence map›Paper›PMID 42185802›Full record

ArticleBMC musculoskeletal disorders2026

Automated assessment of coronal lower extremity alignment on long-leg radiographs using a deep-learning model: validation, efficiency gains, and superiority of an edge-based tibial joint-line definition.

Wenzhong Jin, Xu Jiang, Yushun Tao, Yuqi Hu, Mengning Yan, Liangbin Gao, Kai Xie, Liao Wang, Jinwu Wang

Abstract readValidation Study
In one paragraph

Article in BMC musculoskeletal disorders, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

Authors and funding

9 authors.

Wenzhong Jin *School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
Xu Jiang *Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
Yushun Tao *Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
Yuqi HuThe School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Mengning YanShanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
Liangbin GaoSun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510275, China.
Kai XieShanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
Liao WangShanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China. wangl821127@163.com.
Jinwu WangShanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China. wangjw-team@shsmu.edu.cn.

Funding

China Medical Foundation 2024CMFA11Clinical Research Program from Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine JYLJ201821National Key R&D Program of China 2022YFF1202600National Natural Science Foundation of China 82202680Project of Biobank from Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine YBKB202118Science and Technology Commission of Shanghai Municipality 21S31905500, 22YF1422900, 23S31905900Student Innovation Training Program of Shanghai Jiao Tong University School of Medicine 1521Y034the Fundamental research program funding of Ninth People's Hospital affiliated to Shanghai Jiao Tong university School of Medicine JYZZ219
6 · The paper itself

Abstract

purposeTo develop, validate, and benchmark a fully automated deep learning (DL) system that simultaneously measures 15 coronal lower-limb alignment parameters on standing long-leg radiographs (LLRs) and localizes deformity, and to compare two tibial joint-line definitions for suitability in DL-based measurement.

methodsA retrospective set of 309 anteroposterior standing LLRs was split into training/validation/testing (60/20/20). External generalizability was assessed using 75 independent LLRs from a different scanner and patient cohort. YOLOv5 was used to detect multiple bony landmarks, followed by algorithmic calculation of 15 parameters (e.g., HKAA, mLDFA, mMPTA). Two tibial joint-line definitions were evaluated: Method 1 (line through medial/lateral lowest tibial plateau points) and Method 2 (line through most medial/lateral plateau edges). Accuracy, clinical failure rate (≥ 2° or ≥ 2%), and runtime were compared with expert consensus annotations. Bland-Altman analysis was added to assess measurement bias and clinical agreement.

resultsOn the external dataset, absolute errors for knee phenotype-related parameters ranged from 0.07° to 0.45°. Automated analysis of all 15 parameters took 24.3 ± 0.7 s, reducing time by 89-91% versus manual measurement (p < 0.001). Method 2 produced significantly smaller absolute errors than Method 1 for nearly all parameters (p ≤ 0.005). Clinically significant failure rates were low (0-4.7%) and were significantly lower than an attending physician's for several key metrics on the external set. The distribution of varus/valgus/neutral alignment based on HKAA and extraarticular deformity locations were reported.

conclusionThis DL framework provides fast, comprehensive, and specialist-level coronal alignment assessment on LLRs. An edge-based tibial joint-line definition (Method 2) outperforms a lowest-point definition, improving precision and reliability for DL measurement pipelines, supporting clinically deployable orthopedic imaging AI. Future prospective studies are warranted to validate Method 2 against clinical outcomes including osteoarthritis progression and surgical results.

Indexed as

Deep LearningRadiographyTibiaAdultAgedFemaleHumansMaleMiddle AgedReproducibility of ResultsRetrospective StudiesTibiofemoral JointArtificial intelligenceCoronal alignmentDeep learningLong-leg radiographyLower extremity alignment

Identifiers

PMID42185802
PMCPMC13220375

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.